Attachment for sewing machines



Nav. s, -1925. 1,560,281

A. B. MATTINGLY ATTACHMENT Fok SEWING MACHINES original Filed Feb. 25 ,1915/ 4 sheetsheet -i mull-lmummus r A. B. MATTINGLY ATTACHMENT FOR SEWING MACHINES Tal mid Feb. 25 ,'1915l 4 shets-sheet 2' Nav. 3, 1925.

' 1,560,281 A. B. MATTINGLIY ATTACHMENT FOR SEWING MACHINES original Fneq Feb. 25 ,191s 4 sheets-sneu s Nov. 3, 1925.-

A. B'. MATTINGLY ATTACHMENT FOR SEWING MACHINES Original Filed Feb. 25 ,1915 4 Sheets-Sheet 4 lli Patented Nov. 3, 1925.

narran stares Partnr o.f.Fr1.c`,Ez.

ALBERTUS :e: MATTINGLY, oruEw YORK; `1v. Y.

ATTACHMENT FORSE-WING" MAGHIITES;

Substitute for application Serial No'. 10,505, Iled February 25., 1915i Eencwedticcemher28; 1922. This application. :filed September 1923:

To all. whom z? may. concern:

Be it know-n that I, ALBERTUS: B. MAT- TINGLY, citizen of.. thev 'United States, and.

resident of New. York, in the countyv of New York and `State of New York, have` invented certain new andF useful` Improvements. in Attachments for Sewing Machines, of which the following is a specification.

Ilhisrinvention relates .tol an improvement in attachments. for sewing machines-,and the inventor is aware that the device iszuof a nature similar to that, disclosed in` British Lettersll?atenti\lo.` 17,153 of. 1905, to -I-Iills,

andv UnitedA States Patents No. 412,081, to

Fletcher, No; 990,601, toSeward, and No. 990,610, to Turck, andtheobject is to overcome some of the objectionable featuresof these devices and to further improve the same.

Thisf application is substituted for my prior application, Serial Number 10,505, filed on February 25,1915, and whiohwas renewed lon December 28, 1922.

The principal objects are to provide a device ofthis character to automatically: cut

or slit the cloth just in advance of the stitching or binding of-the button'hole so thatthe needle may pass alternately through the cloth andthen through the slitor cut, thus causing the thread to be brought through the cut and make' a perfect bindingf of` the raw edges of the work, and to provide a. means for positively actuating the knife, so as to give it a quick and decisive action at the proper periods; to make the cut the' proper length according to 'thelength of fthe button-holes, and to have the length of cut automatically adjust itself withthe adjust-A ing of the device for the length of the button-hole.

The further objects are to provide a de` vice of this character which by its construction is considerably reducedinheight and thereby doing away with the necessity ofk removing the face plate of the sewingmachine to adjust the presser bar, andby the construction of the base plate obviating the necessity of removing the' feed dogs of the sewing machine, (both of which things have to be done bcfore'the Hills or Turck devices can be attached to the machine).

The still further objects are to provide an improved ratchet device for yeffect-ing the lateral vibration of the work clamp, to pro duce the overstitch of the edge ofthe but- Serial Noi 662,003;

ton-hole, andto form other parts of thedevice by the stamping process, andby screw machines, j which` are j thev cheapest` methods of manufacturing of this class. H

f AL still further object is to .i provide ai de vice-0f this1 kindrin which the.` knife can be. adjusted; to cuty a` line ori slit in which. the: needle. will follow with tsrinsideflinesv ofl its vibrating motiongon its forward movement and also perform they same function on its-1 backward` movement in forming or` stitching` the, button-ho'le.

With. these` and other objects in view, it; will be seen that I accomplish the foregoing, by referring to the accompanying drawings forming a part ofk this specification; but I do. not wish to confine myself to the exact construction shown, as I have,y for the sake of clear illustration, exaggerated somel of the parts, especially in the side elevations.

In the accompanying drawings, showing one embodiment of'myl invention, Figure 1 is aplan view of the device, Fig. 2 is ay side elevation; Fig. 3 is a horizontal section taken on the line 3 3 of Fig. 2, and show ing diagrammatically the operating cam friction driveor eccentric in dotted lines; Fig. lis a similar View to Fig. 3, showing more clearly the operating means for the knife; Fig. 5 is a similar view toFig. 4, with the knife and its operating meansremoved; Fig. 6v is a` similar view to Fig. 5, with the work clamp and knife guide [and also the retaining washer removed, andshowing the vibrating mechanism; Fig. 7 is a similar view to Fig. 6, showing a part of the vibrating mechanism removed and showing the pawl plate and the adjusting means for the knife, and the adjusting means for controlling the length of throw of the vibrator; Fig. 8 i-s a central vertical section ofthe device; Fig. 9iisglaperspective i view ofthe operating lever; Figs. 10, 11 and 12- are three views' of thel vibrator; Fig. 13 is a pla-n of the vibrator carrier; Figs. 1li and 15v are two views of the knife carrier; Figs. 16 and 1T aretwo vie-ws of the ratchet cam; Figs. 18 and 19 are two views ofthe shield for the knife carrier, and integral therewith the stripper plate for the needle, and the guide for the work clamp', Figs. 20 and 21 are two views of the pawl plate for operating the ratchet cam; Fig. 22. is aplan ofthe work clamp; Fig. 23 is a top plan ofl the eccentric operating mechanism, showing- Cil the adjustable eccentric cam; Fig. 24 is a bottom plan of the eccentric operating mechanism, showing the knife cam and the race cam for operating the work clamp for forming the contour of thebutton-hole when operated in conjunction with the eccentric cam; Figs. 25 and 26 are two views of the retaining washer; Fig. 27 is la plan of the friction washer or plate; and Figs. 28 and 29 are two views of the retaining stud or pivot; Figs. 30 and 31 are two views of the adjustable guide for the alining of the work-clamp with the needle of the sewing machine.

I provide a suitable base plate 1, which is secured to a rear throat plate 2 of the sewing machine in any suitable manner, but preferably screwed thereto, as shown in Figure 1 of the drawings.

The base plate 1 is provided with an ear 3, which is upwardly turned and carries the operating lever 4, which rocks on a pivot 5 formed of a large screw, the lever 4 being provided with a bifrucated end 6, which engages the shank of the screw of the tightening collar of the needle bar of the sewing machine. kThe lever 4 is further provided with an arc-shaped slot 7, through which passes the arm of the friction clutch, which receives its movement from the screw 8 in the ear 9 and the rear end 10 of the slot 7. The screw 8Y is frictionally held from turning by the pressure of the spring 11 against its head and the ear 9. The lever 4 is further provided with an arm or extension which has an upturned bifurcated end 12, which operates the pawl plate 13 by the web portion 14.

The base plate 1 is further provided with a stud or pivot 15, which I have shown screwed into the base plate with its flange or enlargement 16 resting against the plate. Rotatably mounted upon the stud 15 and supported by the flange 16 is the pawl plate 13, (which is swung in an arc by the end 12 of the lever 4 in a forward and backward movement). Rotatably mounted upon the stud 15 and resting upon the pawl plate 13 is a ratchet cam 17, and above this, resting on a shoulder 18 of the stud 15, is the retaining washer 19, and .then the eccentric disk 20 carrying the adjustable eccentric cam 22, which is held in position by a T-bolt 23 and lock nut 24. The top of the stud l5 is provided with a friction washer 25, which is prevented from turning by the flat 26 of the washer and the fiat 27 of the stud. The friction is caused by the tightening of the screw 28 of the stud, which causes the washer to press the disk 2O against the retaining washer 19.

The base plate 1 is further provided with a cut-away portion 29 having an ear 30 bent horizontally, and slightly above the bottom level of the base plate. Passing through the slot 31 in the ear 30 is a screw 32 screwed into an L-shaped member 33 which has a slot 34 and an upturned ear 35 for adjusting it while the screw 32 is loose. The slot 34 is for receiving the bottom end of the pin 36 of the L-shaped inember 37, which is provided with a slot 33 for .adjusting it upon the base plate 1 by the screw 39, and it is also provided with an upturned ear 40 for adjusting it while the screw 39 is loose. The pin 36 is tight in the member 37 and its upper end forms a pivot for the vibrator 41, which is connected thereto by the hole 42 in the ear 43, and when assembled the ear 43 is capable of passing under the pawl plate 13, while the yoke 44 straddles the ratchet cam and rests upon the pawl plate 13.

The vibrator 41 is provided with an upturned bifrucated ear 45, which has two notches 46 in which slides the rear yoke 47 (of the work clamp 48), which st raddles the stud 15 and rests on the retaining washer 19, which working in conjunction with the slots or notches 46 keeps the forward part 49 of the work clamp in proper contact with the base plate 1 and prevents the bottom stripper plate 50 from leaving the slotted way 51 in the base as it is oscillated by the work clamp in connection with the ears 52.

Mounted upon the yoke 47 is the guide or shield 53 for the knife carrier 54, having its front end 55 in the form of a stripping plate which slides in a groove or space 56 formed by a plate 57, which is forced into the upper jaw 58 of the work clamp. The rear end of the shield 53 is enlarged, forming a guide 59, by means of the downwardly extending flanges 60 fitting the yoke 47, which moves back and forth relatively to the stud 15. The rectangular opening 61 is of a width equal to the diameter of the upper end of the retaining washer which passes through it and prevents the sliield from moving back and forth but allows its rear end to be drawn laterally of the stud 15 in both directions by the pin 62 working in the cam groove 63 formed by the cams 64 and 65, (thus causing the vibrator to vibrate or oscillate the work clamp in the shape of a button-hole while the eccentric is moving the Vwork clamp back and forth the length of the button-hole).

Mounted upon the guide 59 is the knife carrier 54, which has its spring portion 66 passing through the openings 67 and 68 of the shield 53. The spring portion 66 has its outer end bent upward, with two ears 69 forming a pair of jaws for the knife 70, which is held by a pin or screw 71. The rear end of the spring portion 66 is formed in a rectangular frame of yoke 72 having a flange 73 forming a cam face 200 against which the cam 74 works, and the flexible portion 7 5` which vinsures the keeping-'of the cain 74:2 and the cam face r200 always in contact. At a predetermined point the ilange 73 forming thecam faceQO() is cut away or ends as at 201, and the yoke is so formed at this point as-to have a clearance space 202 to prevent the yoke frame fromhittingthe cam 74 when the flexible party 75 of the yoke causesthe yoke and knife to move quickly back between the strokesof the needle and thus prevent the needle bar from strikingthe knife several'times while it is being moved back from under 'the needle bar. This quick inoveinentfis causedl by the cain 74, which holds the yoke forward for the proper time, having an abrupt drop 203, sothat while it isv revolving on they studl the point 20%- passes the point :205 on the cain face Q00; The face 206 is so formed as to not interfere with the cani face 2G() and thisallows the yoke to move back-withlitsfull stroke at this point, which is laccomplished on the upward stroke of the needle bar.

The work clamp is provided with an eccentricyoke or member 7 6 having an elongatedopening 77 in which works the adjustable eccentric cam 22 against the faces 7 8 and 79. (The revolving of the cam 22 aroundthe stud lca-uses the work clamp to be moved'lback and forth relative to the needle.) rllie member 7 6 is securedto the work clamp 48bymeans of screws 80, and the forward end is bifurcated and bent so as to `form'bearings forl the locking member 81, whichis formed of aibent wire having acentral'portion 8Q'which acts in the capacityfof hand lever to operate the two end portions 83, which act upon the spring extensions 84 (of the uppei jaw 58) and which are riveted to the rear yoke 47 of the work clamp.

Mounted on the base plate 1 (see Fig. 7) is a springmeinber 85, which isl held=in pesi tion bythe screws SGland has an upwardly extending portion 87, which extends through the opening 88 of the pawlplate 13 andinto the holes 89 of the ratchet cam 17. This prevents theratchet cam from beingfturned backwards by frictionoftlie pawl 90 slippingoiit of any one of the holes 89' u-pon its backward movement after it has revolved the ratchet cam onetenth ofaturn.

lhe eccentric disk isrevolvedby al fr-iction'device 91 consisting of a ring 92 carryinga frictionv dogl 93 which tui'iison a pivot 95 and isheld in its biting'position by a spring 9i. The operation of the friction device will be subscribed later on.

rlhe base-plate is further bent or formed so as `tohave a raisedportion=97 through the center thereof, upon which the bottom of the work clamp slides and? on which is cut:

l the channel or' groove 51 for thev stripper plate 50, which has an opening 98-somewhat in the shapeofa T'. Beneath'tlie stripper plate 5() in the basefplatef is an opening 99j to allowy the needle to Iperforml `its! functions.

Thel raised portion 97 fornis ai channel or groove 100 (see Fig. 8), which allows-the freeI action of the feeddo'gs' offthe sewing machine and' raises the device enough to permit the-cuttingof the cloth without the knife hittingV the' dogs on its downward isreinoved and-thedevice is slippedfliniits place by' the `insertion *ofy the` throat` platee@-f which is screwed to vthe device, andltlieshank oi` thescrew which holds the needlein position passes into the bifurcated endy of the lever 41 To `make a button-hole;` the worki clamp =is set by operating the'r sewing machine untilI the extreme back position oftheworkelafmp L is reached'an'd the needle is'initseX-treme upper position. member 81 is `then' pressedfforward; (thatfis,

inthe direction of the'nee'dle), andforces'f the' ends 83 backwards andthusrellieves the pressure of the springs "84e, whicliallowsthe jaws of the' work clamp to open; 'Ihe'fcloth` is inserted between the jaws andthelever 82I pushed back to its original position', thus causingthe upper jaw to force' they cloth;

down into theconcave-o'pening inthe-lower Jaw, and at the same time-the flanges 96 of the upper jaw prevent the" slippingoff the cloth on' the lower jaw and thus" causes the" cloth to' bey stretched like drumheads Nith the work clamp in this position the knife is in the' dotted position shownF44 in Fig: 2, and upon running the inachiiie'theI needle bar` strikes the top oftheknifeand forces it through the cloth each time the needle descends, until theJ work` clamp isalmost atn it's extreme forwardpesition, when 41. lith each upward movementofi` thev needle bai the lever 4l israised, which in turn swingsthe pawl plate 123 suliiciently to have the'pawl-Q@ enter one of the holes 89 ofi theratchet cani andfrevolie it one tenth of? The lever 82 of the lockinglCO a revolution, whicli'causesone oflthefpointed cam faces 101" to act on one-side ofthe' yoke 44 and cause the vibratorto swingtooneside on its pivot/536. The face-*lOzZ-"preven-ts any overthrow of" the vibratr. The'next stroke of the needle causesone of the pointed faces 101 to act on the opposite side of the yoke 44: and swing it in the opposite direction. This movement of the vibrator causes the work clamp to be oscillated on its pivot 62, such motion being transmitted through the ear l5 of the vibrator. Thile the vibrator is oscillating` the work clamp in one direction or the other with every stroke of the needle to make the needle pass first through the cloth and then through the cut, the eccentric cam is slowly shoving the work clamp forward the length of the button-hole, the speed of the forward movement being regulated by the screw 8, which strikes the arm 93 of the friction clutch and forces the ring 92 back a predetermined amount, (upon the downward stroke of the needle). The rear end of the slot 7, upon reaching the arm 93, (on the upward movement of the needle), forces the ring to move forward and the nose 103 to bite into the eccentric disk 20 and cause the eccentric disk to revolve, which causes the point 109 of the cam 22 to act upon the face 7 9 of the member 76 and shove the work clamp forward, and when the cam point 109, on the last half of the revolution of the eccentric disk 20, works against the face 78, it causes the work clamp to be drawn backwards. -The revolving of the eccentric disk 20 causes the pivot 62 to shift its position relatively to the ear and the stud 15. On the first part of the revolution of the disk 20 the pivot pin 62 is in that position of the cam groove 63 designated by the numeral 103, which causes the first straight part ofthe button-hole to be made. The parts 104 and 105 cause the pin 62 to first move further away from the stud and then closer to the stud than it was at the start. This causes the eyelet of the button-hole to be made, andthey part 1,06, causes the pin to Stand still Lmtil the'last straight part of the button-hole is finished, and the movement of the pin caused by the part 107 causes the two straight sides of the button-hole to be stitched together.

In order to make a large button-hole, the eccentric cam 22 is located out at` the periphery of the disk 20, and the nearer the center of the disk the cam 22 is located the smaller will be the button-hole; but no matter what the length of the button-hole is the knife will always move from under the needle bar at the same period ofthe operation of making the' button-hole and will be pushed under the needle bar at the starting point, so that the slot will always be the proper length. Then a large button-hole is made its overstitch should be of greater length than for a small one, so that by loosening the screw 39 and drawing the member 37 back it causes the ear l of the vibrator to be moved nearer to the pin 62 upon which the work clamp oscillates, and causes a longer throw of the work clamp, or by mov ing the member 37 forward the throw of the work clamp is decreased.

To line the device up with the needle of the sewing machine the screw 32 is loosened and the member 33 can be moved in either direction, thus carrying the pivot center of the vibrator to a position which will cause the knife to line up with the needle on the strokes which pass the needle through the cut.

What I claim for my invention is:

1. rlhe combination with a frame and a work clamp mounted to reciprocate thereon and to vibrate laterally, of a stud, a ratchet cam with five points and working faces mounted on the stud, means for advancing the ratchet cam step by step, the work clamp having a vibrating means connecting it to the ratchet cam, a knife shield carried by the work clamp and movable thereon, a spring member, a knife carried by the spring member adapted to be forced through the material by the needle bar, a yoke formed on the end of the spring member, a rotating cam on said stud, a cam face formed on said yoke and acting in conjunction with the rotating cam on the aforesaid stud, and a spring formed on said yoke for operating the knife at the proper time and withdrawing it from under the needle bar.

2. The combination with a frame and a work clamp mounted to reciprocate thereon and to vibrate laterally, of a stud, a ratchet cam with five points and working faces mounted on the stud, a pawl plate for advancing the ratchet cam step by step, the work clamp havin()v a vibrating means connecting it to the ratchet cam, a knife shield carried by the work clamp and movable thereon, a spring member, a knife carried by the spring member adapted to be forced through the material by the needle bar, a yoke formed on the end of the spring member, a rotating cam on said stud, a cam face formed on said voke and acting in conjunction with the rotating cam on the aforesaid stud, and a spring formed on said yoke for operating the knife at the nroper time and withdrawing` it from under the needle bar.

3. The combination with a frame and a work clamp mounted to reciprocate thereon and to vibrate laterally, of a stud, a ratchet cam -with five points and working faces mounted on the stud, a pawl plate for advancing the ratchet cam step by step, the work clamp having a vibrating means connecting it to the ratchet cam, means for preventing any backward throw of the ratchet cam, a knife shield carried by the work clamp and movable thereon, a spring meniiber, a knife carried by the spring member adapted to be forced through the mit te-rial by the needle bar, a yoke formed on the end of the spring member, a rotating mounted on the stud, a pavvl plateffor. ad-

vancingthe ratchet cam step by s'tep, the Work clamp-havinga vibrating means connecting it to the ratchet cam, means for shifting at certain yperiods' the pivot upon which the Work clamp oscillates to form a` button-hole with a loop to makel an eyelet end, a knife shield carried vby the Work clampand movable thereon, a spring member,-a knife carried bythe spring member adapted tobef forced through thef material by the needle bar,"a yoke formed von the `end of the spring member, a rotating cam. on

said stud, afcamffacefformed on lsaid yoke and acting .in conjunction With the rotating cam on the `aforesaid stud, and a "spring formed on saidyoke for operating the knife atthe proper timeiand'av'ithdrawing it from. Vunder the needle bar.

They combination `vvith a frame and a Work clamp lmounted to reciprocate thereon andtol vibrate laterally, of a stud, a ratchet cam Iwith 'five -poinftsland Working faces mounted Onthestu-d, a pavvl platefor advancing the raftchetfcam,4 'step by step, the Work clamp@ havingfa vibrating means' connecting it -tofthe ratchet cam, meansfor preventing any backward throw/of the ratchet cam, means for shifting at certain periods the pvot "uponfivlneh the 'Werk lf clamp oscillates to form a button-hole With a loop to make an eyelet end, a knife shield carried by t-he Work clamp and movable thereon, a spring member, a knife carried by the spring member adapted to be forced through the material by the needle bar, a yoke formed on the-end of the spring member, a rotating cam on said stud, a cam face. formed on said yoke and acting in conjunction With the rotating cam on the aforesaid stud, and a spring formed on said yoke for operating the knife at the proper time and Withdrawing it from under the needle bar.

6. The combination With a frame and a Work clamp mounted to reciprocate thereon and to vibrate laterally, of a stud, a ratchet cam with five points and Working faces mounted on the stud, a pawl plate for advancing the ratchet cam step by step, the work clamp having a vibrating means connecting it to the .ratchet cam, means for shifting at certain periods the pivot upon which the Work clamp oscillates to form a button-hole With a loop to make an eyelet end, means for increasing or ,decreasing the overstitch or therlateral throiv of the Work clamp, a knife shield carried by the Work clamp and" movable thereon, a spring member, a knife carried by the spring member adapted to be forced through the material bythe needle bar, a yoke formed Aon the end of the spring member, a rotating cam on lsaid stud, a cam face formed on said `yoke `and acting in conjunction With the rotating cam v on i the aforesaid stud, and a` spring formed on saidyoke for operating the knife at the proper time and withdrawing it from under the needle bar.

7. The combination lWith a frame anda Work clamp mounted to reciprocate thereon and to vibrate laterally, ofa stud,,a ratchet cam with iive points and Working faces mounted on the stud, a paWl plate for advancing the ratchet cam step by step, the Work clamphav-ing a vibrating means'connecting it to the ratchet-cam, Vmeans for pre venting any backward throvv ofthe ratchet cam, means for shifting at certain periods the pivot upon which the Work clamp oscillates to form a` button-hole with a loop to -makean eyelet end, means' for increasing `or decreasing the over-stitch or the lateral throw of thev Work clamp, aiknife shield carried by the Work clamp and movable thereon, a spring member,-

knifeica-rried by the spring member adapted to be forced through the material by the needle bar, `a yoke formed on the end of the spring member, a rotating cam, on said stud, a cam face formed on said yoke and acting in conjunction With the rotating cam on thei aforesaid stud, and a .spring uformed on said yoke for operating the knife atf the proper time nd withdrawing it fromnnder the needle 8.l The combination with a frame and a Work clamp mounted to reciprocate thereon and to vibrate laterally, of a stud, a ratchet cam With five points and Working faces mounted on the stud, a pavvl plate for advancing the ratchet cam step by step, the Work clamp having a vibrating means connecting it to the ratchet cam, means for shifting at certain periods the pivot upon Which the Work clamp oscillates to form a button-hole With a loop to make an eyelet end, means for increasing or decreasing the overstitch or the lateral throw of the Work clamp, means for adjusting the vibrating means relatively to the stud and needle, a knife shield carried bv the Work clamp and movable thereon, a spring member, a knife carried by the spring member adapted to be forced through the material by the needle bar, a yoke formed on the end of the spring member, a rotating cam on said stud, a cam face formed on said yoke and acting in conjunction with the rotating cam on the aforesaid stud, and a spring formed on said yoke for operating the knife at the proper time and withdrawing it from under the needle bar.

9. The combination with a frame and a work clamp mounted to reciprocate thereon and to vibrate laterally, of a stud, a ratchet cam with five points and working faces mounted on the stud, a pawl plate for advancing the ratchet cam step by step, the work clamp having a vibrating means connecting it to the ratchet cam, means for preventing any backward throw of the ratchet cam, means for shifting at certain periods the pivot upon which the work clamp oscillates to form a button-hole with a loop to make an eyelet end, means for increasing or decreasing the overstitch or the lateral' throw of the work clamp, means for adjusting the vibrating means relatively to the stud and needle, a knife shield carried by the' work clamp and movable thereon, a spring member, a knife carried by the spring member adapted to be forced through the material by the needle bar, a yoke formed on the end of the spring member, a rotating cam on said stud, a cam face formed on said yoke and acting;` in conjunction with the rotating cam on the aforesaid stud, and a spring formed on said yoke for operating the knife at-the proper time and withdrawing it from under the needle bar.

10. The combination with a frame and a work clamp mounted to reciprocate and to vibrate, of a cam having a series of arc faces meeting at-points and having a concentric circular series of perforations double in number to the said faces, and advancing means arranged to engage said perforations to engage the cam atsaid perforations to turn the cam step by step, the work clamp having a vibrating means connecting it to the ratchet cam, a knife shield carried by the work clamp and movable thereon, a spring member, a knifecarried by the spring member adapted tol be forced through the material by the needle bar, a yoke formed on the end of the spring meinber, a stud, a rotating cam on said stud', a cam face formed on said yoke and acting in conjunction with the rotating cam on the aforesaid stud, and a spring formed on said I yoke for operating the knife at the proper time and withdrawing it from under the needle bar.

1l. The combination with a frame and a work clamp mounted t0 reciprocate and to vibrate, of a cam havinga series of arc faces meeting at points and having a concentric circular series of shoulders double in number to the said faces, and advancing means arranged to engage said shoulders to turn the cam step by step, the work clamp having` a vibrating means connecting' it to the ratchet cam, a kknife shield carried by the work clamp and movable thereon, a spring member, a knife carried by the spring member adapted to be forced through the material by the needle bar, a yoke formed on the end of the spring member, a stud, a rotating cam on said stud, a cam face formed on said yoke and acting in conjunction with the rotating cam on the aforesaid stud, and a spring formed on said yoke for operating the knife at the proper time and withdrawing it from under the needle bar.

Signed at New York in the county of New York and State of New York this 10th day of September A. D. 1923.

ALBERTUS B. MATTINGLY, 

